While substantial effort and attention continues toward the development of newer and more sustainable energy supplies, the conservation of energy by increased energy efficiency remains crucial to the world's energy future. According to an October 2010 report from the U.S. Department of Energy, heating and cooling account for 56% of the energy use in a typical U.S. home, making it the largest energy expense for most homes. Along with improvements in the physical plant associated with home heating and cooling (e.g., improved insulation, higher efficiency furnaces), substantial increases in 5 energy efficiency can be achieved by better control and regulation of home heating and cooling equipment. By activating heating, ventilation, and air conditioning (HVAC) equipment for judiciously selected time intervals and carefully chosen operating levels, substantial energy can be saved while at the same time keeping the living space suitably comfortable for its occupants.
Some thermostats offer programming abilities that provide the potential for balancing user comfort and energy savings. However, users are frequently intimidated by a dizzying array of switches and controls. Thus, the thermostat may frequently resort to default programs, thereby reducing user satisfaction and/or energy-saving opportunities. One such configuration difficulty is setting the time-of-day. This is complicated by different time zones and daylight savings time and changes thereto. Controlling HVAC equipment is often time-of-day based. When the time-of-day is not set, elegant control of the HVAC equipment is hampered.